that was literally the thing I was most excited abt this season and it kinda sucks I couldn’t get it 
I even tried deleting the files and stuff but it didn’t work. Oh well, it’s just a helmet I guess:( anyone else didn’t get the chance to obtain it?
Honestly, I never had a problem getting the helmet.
It’ll be available in The Exchange store at some point from Season 7 onwards.
You may have missed out now but there’ll be opportunities to buy it later on.
I managed to get it on my 57th try, but with The Exchange coming next Season it might be on there to Purchase
I don’t have it, but that is because I haven’t actively tried to complete the challenge. Actually, I finally got Reach on the MCC for this challenge, however, I decided that instead of going straight to the Pillar of Autumn mission, I would play through the campaign and look for other opportunities to complete it. Well, I didn’t try very hard, so I still haven’t done it. Ha ha…
I still have a bit of time before the challenge is gone, so I won’t resort to the Pillar of Autumn just yet. I think the final part of Tip of the Spear could be a good candidate. Yes, that might just work!
How I did it was sprint off cliff, cancel sprint, hold crouch, look down, make sure to land on top of the elite (my mistake was I kept landing behind him), and trigger an assassination animation at just the right moment when right on top of him. The timing has to be perfect it seems. There is a good walk thru in my signature that helped me.